Reading this strong debut collection of 16 very short stories and one long novella is like browsing through an album of stark black-and-white photographs. Thematically linked by the joblessness referred to in the title and by the fact that the main characters define who they are by what they do, the tales depict a middle-class world in which every disruption of routine causes a sea-change in character. The loss of their canoe in ``Fishing Trips'' leads two men to choose to live in the wild; the novella ``Glass'' shows a painter's life turned upside down when he loses his apartment and his sponsor; a divorced chemical plant employee enters a world of violence and hallucinations in the brief, haunting ``A History of Amnesia,'' which reads like part of a lost Don DeLillo novel. Most of these pieces are word pictures rather than stories; plot, mood and character take second place to a bare-bones presentation of speech and action, as in ``Lesson,'' ``President'' and ``Floodlight.'' Mulcahy's voice, whether first- or third-person, is sharp and precise; the narratives proceed in blocks of sentences like quick, hard-hitting punches, creating a whole that is much more disturbing than its disparate parts. ( Aug. )